Writing feverishly, in crisp words, Richard Boyer rises above the tweedy objectivity of New Yorker profiles to tell the searing story of American seamen and the union they have built. The seamen are workers at sea, not comic opera swashbucklers, and the union they have put together is the N.M.U., certainly no joke. It is a story of men who are reweaving the country's social fabric, men who think about democracy a good part of the time and who act on their thought. The book is called "The Dark Ship," because that is the kind of title that sells books. It should have been called by the title of its second part, The New American, because essentially it is the story of new men and the unions that renewed them.

This is an up from serfdom story, relating the upward surge of beaten-down seamen to a position of self respect and the only dignity they have ever known. The Union, says Boyer, has gotten the men something they can put in their wallets, and in their stomachs. It has given them something to think about, a purpose. But more important, it has done something for the people as people, restoring to them a belief in themselves and in the possibilities of social action. There is a new kind of man in America, the union man. He is the forecast of our future. Of this Boyer is sure. He is sure that the modern union movement means a sea change in the American collective personality.

Workers who were once beholden to their bosses were not much more than industrial serfs, says Boyer. They lived in fear and depended on the big smile and the well-shined shoe for their future. Now they depend on their union, which means that they depend on themselves. This change in the workers' mentality is the democratic dynamic of our time. Some day historians will note the change, and this skillfully written book will be one of their sources.

"The Dark Ship" tells the story of this union from the inside. For all their significance in the American scene, the details of what a union is and how it operates are not well known. The confusion in Congress is proof enough of that. Even the hydra-headed collosi we know as corporations are more familiar, and often more respected. After a brilliant reporting job on a crew and its union activity at sea, Boyer describes the union as a working democracy, as part of the lives of its members, and not as simply a far-away bureaucracy which has lost touch with the people it represents.

Boyer takes the word "union" out of the newspaper vacuum and puts it in terms of the history, structure and functions and personalities of a labor organization. In vivid concreteness he shows the union organizing, educating, providing social service, operating a hiring hall, running strikes, bargaining collectively, handling grievances and publishing a newspaper. In short, sharp sketches he shows union men and their leaders as human beings.

For all its careful detail, the book is not complete. Boyer ignores the internal political frictions that have ripped the union from the start. He makes the simple assumption that the N.M.U. is a representative American union. It is not. Not many unions are as militant or as politically conscious. Not many union men manage to combine so much thought and action in their lives. In these respects Boyer sometimes writes naively. But it is a full and important book.